Which one of these is correct to evaluate the mean standard deviation of the process samples?
Posted: Thu Jul 14, 2022 1:47 pm
a) \(\bar{s} = \frac{\sum_{i=1}^m (n_i-1) s_i^2}{\sum_{i=1}^m n_i}\)
b) \(\bar{s} = \left[\frac{\sum_{i=1}^m (n_i-1) s_i^2}{\sum_{i=1}^m n_i-m}\right]^2\)
c) \(\bar{s} = \left[\frac{\sum_{i=1}^m (n_i-1) s_i^2}{\sum_{i=1}^m n_i-m}\right]^{1/2}\)
d) \(\bar{s} = \frac{\sum_{i=1}^m (n_i-1) s_i^2}{\sum_{i=1}^m n_i-m}\)
b) \(\bar{s} = \left[\frac{\sum_{i=1}^m (n_i-1) s_i^2}{\sum_{i=1}^m n_i-m}\right]^2\)
c) \(\bar{s} = \left[\frac{\sum_{i=1}^m (n_i-1) s_i^2}{\sum_{i=1}^m n_i-m}\right]^{1/2}\)
d) \(\bar{s} = \frac{\sum_{i=1}^m (n_i-1) s_i^2}{\sum_{i=1}^m n_i-m}\)